US Secretary of State John Kerry met Pakistani Prime Minister Nawaz Sharif at the United Nations and "the two discussed the incident.
The Secretary urged Pakistani cooperation in the investigation," the State Department official told PTI on condition of anonymity.
The US, the official said, is awaiting further information as to who were behind these attacks and has offered its assistance to India on this.
"We are still awaiting further information. We have offered our assistance to the government of India, and we also urge Pakistan to cooperate in the ongoing investigation," the state department official said.